To provide a central measure of orienting for use in the diagnosis of psychiatric patients, properties of the 0-wave (orienting wave), a slow brain potential, are examined in normal young adult volunteers. The structure and scalp distribution of the 0-wave component of the Contingent Negative Variation is characterized during varying stimuli durations and rates of presentation and with regard to its covariation with autonomic measures, the time course of habituation, and the sleep-waking cycle. Heart rate, pupil measures, glavanic skin responses, electroculogram, respiration, electromyogram, and pulse are measured along with several channels of electroencephalogram recordings.